curtis



4 Sheets-Sheet 1.

G. G. CURTIS 85 S. S. WHEELER. HYDRAULIG ELEVATOR. No. 266,108. PatentedOct-.17, 1882.

(No Model.)

I (No Model.) 4SheetsS heet 2. G. G. CURTIS & S. S. WHEELER.

HYDRAULIG ELEVATOR.

Patented 001;. 1'7, 1882.

Gum bum/L (No Model.) 4 Sheets-Sheet 3. O. G. CURTIS 81S. S. WHEELER.

HYDRAU ELEgATOR.

FIG-5 (No Model.) 4 Sheets-+Sheet- 4. 0. G. CURTIS WHEELER.

HYDRAULIC ELEVATOR.

No. 266,108. Patented O0t.17, 1882.

Qdimm b.

llNrTEo STATES PATENT rrrca.

CHARLES Gr. CURTIS AND SOHUYLER S. WHEELER, OF NEW YORK, N. Y.

HYDRAULIC ELEVATOR.

SPECIFICATION forming part of Letters Patent No. 266,108, dated October17, 1882.

1 Application filed February 6, 1882. (No model.)

To all whom it may concern Be it known that we, SOHUYLER SVHEELER andCHARLES G. CURTIS. citizens of the United States, residing at New York,in the county of New York and State of New York, have invented new anduseful Improvements in Hydraulic Elevators, of which the following is aspecification.

Our invention relates to that class of elevators which are operated bymeans of hydraulic pressure acting in a cylinder upon a piston connectedto the elevator-car, either directly or through a system of ropes andpulleys, and in which the motion of the car is controlled by theoperation of a valve or valves, the effect ofwhich operation is to allowthe pressure to act on one side of the piston or on both sides,according as it is desired to raise or to lower the car. Such elevatorsconsists generally of a vertical cylinder, in which works a pistonconnected to the car, a stand-pipe leading from the water-supply to thetop of the cylinder, a circulating-pipe leading from the top to thebottom of the cylinder, a discharge pipe leading from the bottom of thecylinder, and a valve operated from the car by means of a valve-rope,through which valve the circulating and discharge pipes communicate withthe bottom ofthe cylinder. This valve has three positionsone openingcommunication between the bottom of the cylinder and thecirculatingpipe, another opening communication between thedischarge-pipe and the bottom of the cylinder, and a third shutting offall communication. Supposing the car to be at the top of theelevator-shaft and the piston at the bottom of the cylinder, and it isdesired to cause the car to descend, the valve is set so as to allow thewater above the piston to circulate around into the lower part of thecylinder, filling up the space below the piston and exerting an upwardpressure which neutralizes the downward pressure above the piston, andconsequently allows the car to descend by its own weight.

In order to raise the car the circulation is shut off, and the column ofwater below the piston allowed to discharge and act by suction upon thedescending piston, which effect, added to the weight of the column ofwater above, produces a constant driving-pressure upon the piston. Whenthese apparatuses become large, and especially when the speed at whichthe car moves gets to be high, the living force or energy of the movingmasses becomes so great as to render it a matter of considerableimportance to stop the car gradually, in order to avoid the strain tothe machinery caused by the sudden stoppage of so great a mass ofmatter. For example, in elevators as now constructed the car when loadedsometimes weighs two thousand five hundred pounds, and moves at a speedof from four to live feet per second. This, if stoppedin a space of sixinches, would produce a pressure of over two thousand pounds, which,added to the weight of the car, would increase the strain on the leadersor hoisting-ropes to four thousand five hundred pounds. The strain onthe valve, cylinder, and pipes would be correspondingly increased.

To avoid the injurious effects thus produced, thereby rendering itpossible to increase the speed at which the car moves,to avoid thedisagreeable sensation caused by a sudden downward start of the car, andto cause the car to be brought to a standstill exactly as its platformreaches the level of the floor are the chief objects of ourimprovements. These objects we accomplish by interposing between thecontrolling device, which the operator himself manipulates, and thevalves of the hydraulic cylinder an automatic mechanism constructed toclose and open the valves at fixed uniform speeds, so as to stop the carwith a uniformlydiminishing motion, and to start itwith auniformly-increasing motion. In this way the direct operation of thevalves, which it becomes very important to have properly performed infast-moving elevators, is taken out of the hands of the operator andmade entirely automatic, the controlling mechanism only enabling theoperator to determine the level at which the car shall stop. Toaccomplish the first two objects we employ a small supplementarycylinder and piston, which is controlled from the car and worked bywater under pressure to operate the main valve. By these means, andindependently of the manner in which the valverope is handled in thecar, we cause the valve to close gradually and regularly, so that thecar becomes stopped without subjecting any of the parts to excessivestrain. The third object we accomplish by bolting small shoulders i orlugs on the valve-rope, one at each floor, in

such positions that they are struck and the valve-rope moved by the carin time to cause the main valve to close and stop the car at the desiredfloor. .VVhen the speed of the car is very variable we make use of thevalve-rope to close the main valve directly by means of lugs; but wemake the ports of the valve of apeculiar shape, so that as the speed ofthe car diminishes the area of the valve-port will decrease at aconstant rate,and therefore the car will be stoppedin the desiredmanner.

Our invention also embraces other improvements, which are: an apparatusfor regulating the amount which the valve may be opened, so that the carwill descend at a fixed speed whateverload it maycontain, and anautomatic arrangement whereby, should the valve-rope fail to work, thecar will be gradually stopped before striking the end of theelevator-shaft.

In the accompanying drawings, Figure 1. is an elevation of a hydraulicelevator, showing the main valve operated by a supplementarycylinder,accordingtoourimprovements. Figs. 2 and 3 are details of thesame. Fig. at is a detail drawing of the supplementary cylinder. Fig. 5is an elevation of a hydraulic elevator, showing the main valve moveddirectly by the valve-rope, with peculiar ports, according to ourimprovements. Fig. 6 is a diagram showing the shape of these ports; andFig. 7 is an elevation of our automatic device for regulating theopening of the main valve according to the load in the car.

The same letters of reference refer to the same parts in all the figuresexcept Fig. 7.

In Fig. 1, B is the elevator-car; A, the hydrauliccylinder;lVLthestand-pipe; N,the cir culating-pipe; U, the discharge-pipe; and O,the main valve. The connection between the car and the piston-rod is nothere shown, but may be made in any well-known manner. The mainvalve,which may be of any form, but preferably balanced, has as we havealready explained three positions. In its lowestposition it admits thewater from the circulating-pipe into the cylinder below the piston,whichcauses the car to descend; in its middle position it shuts off allcommunication with the lower part of the cylinder, which causes the carto stop; and in its highest position it allows the water below thepiston in the cylinder to discharge, which causes the car to ascend. Ourimprovement here consists in operating this valve by means of asupplementary hydraulic piston and cylinder, D, the valve of which is ofpeculiar construction, and is worked directly from the car B by thevalve-rope K acting through a rack and pinion, J W. Bythe use of thissupplementary cylinder in operating the main valve we secure a gradualand perfectly uniform closing and opening of the main valveindependently ofthe mannerin which the valverope is handled by theoperator in the car, the important advantages of which we have alreadyenumerated. In order to make the car stop with its platform exactly atthe level of the desired floor, and to do this automatically,

the forkjust as the valve has closed we bolt small shoulders or lugs Itonto the valve-rope K, one at each floor, in such positions that theywill be struck by a fork, S, on the car and carried along with it, thusworking the supplementary valve which admits water to the supplementarycylinder in time to close the main valve and stop the car as it reachesthe level of the desired floor. In order that the fork S may not strikethe lugs R in passing until. the car arrives at the floor T at which theoperator wishes to stop, the fork S is shaped as shown in plan in Fig.2, (which is a section on line a" z,) and set in guides, so as to becapable of being moved toward or away from the valv'e'rope K by thelever U When the fork S is thrown forward, as shown in Figs. 1 and 2,the valve-rope K, which is guided bya collar inthe bottom of the car,passes through the slotVuntil the fork S comes to one of the lugs Itwith which it engages, thereby moving the valve-rope and working thesupplementary valve. Then the fork is withdrawn the valve-rope K passesthrough the fork S where the opening V is large enough to allow the lugsto pass without striking, and the car moves on without affecting thevalve. Consequently when the car is to be stopped at any floor the forkS must be thrown forward after having passed the floor next above orbelow and before reaching the lugsRcorresponding to the floor where thecar is to be stopped. In thus operating the main valve by means of thesupplementary cylinder it is necessary that the supplementary valveshould be closed by the valve-rope and remain closed until the mainvalve becomes closed, during which time, if the fork were to remainengaged with the lug, the valve-rope would be carried far enough tothrow the supplementary valve the other way, the effect of which wouldbe to move the main valve in the opposite direction. To obviate thisdilliculty we place inclined surfaces Y, one above and one below eachtloorT, against which surfaces the fork S strikes and by which it isthrown back, so as to disengage it from the valve-rope K and allow thecar to proceed to the floor without carrying the valve-rope with it.These surfaces Y are placed in such positions that they free thevalve-rope from the supplementary valve. The fork S should be be tweencushions or springs, as shown in Fig. 3, in order to impart the velocityof the car to the valve-rope by degrees, and so avoid the shock whichwould otherwise occur when the fork S struck the lug R.

The construction of the supplementary cylinder and valve is shown inFig. 4 in its application to the main cylinder and valve, in which A isthe main cylinder; (1, the main valve; 1), the supplementary cylinder;L, the piston; I, the main-valve stem and piston-rod ot'supplementarycylinder; 0, the slide-valve of supplementary cylinder, worked directlyby the valve-rope K through the rack J and pinion. V. This valve a,controlling the flow of water to and from the cylinder D, is so designedthat when occupying its highest position it allows water to'flow tromthe branch Q of the circulating-pipe N through the port a into the lowerpart of the cylinder D, and the water in the cylinder 1) above thepiston L' to discharge through the port I), the orifice din the valve 0,and the discharge-pipe This causes the piston to raise the main valve.1n its lowest position it allows water to enter by the branch pipe 1?through the port b above the piston L, and the water below the piston todischarge through the port a and orifice d of valve 6 and thedischarge-pipe f. This causes the piston L to draw down the main valve.In its central position it shuts off the flow of water from thesupply-pipe and opens communication between the two ends of the cylinderthrough the ports a and b. This allows the piston L to .return to itscentral position, whither it is impelled by the weighted arms E and F,which act upon the valve-stem I in the following manner: The weightedarm E, pivoted at i, (see also Fig. 1,) bears on a pin fixed to acollar, It, on the piston-rod I, on which it exerts a downward pressureuntil the collar k descends far enough to allow the arm E to rest on thestop g. Similarly the arm F, pivoted atj, exerts an upward pressure onthe pin of collar is until it rises far enough to allow the arm F torest on the fixed stop h. Thus there is always a pressure from one ofthe weights G or H tending to force the main valve back to its centralposition. Thesizeot'the passages b and a, through which the water isthus forced from one end of the cylinder D to the other, being fixed,the speed at which the main valve closes in either direction isdependent upon the pressure of the weighted arms upon the collar k, andmay easily be set to suit the speed of the car by sliding the weightsalong the arms. The speed of opening the main valve may also be set tosuitthe comfort of the passengers by placing cocks or valves in thesupply-pipes P and Q.

The method hereinbefore described of working the main valve of ahydraulic elevator by means of a supplementary cylinder and pistoncontrolled from the car will not operate successfully without somemodification or the addition of a speed-governor attached to the carwhen the speed of the car is otherwise variablethat is to say, when thespeed is sometimes greater or less, depending upon the load in the car.Under these circumstances we prefor to operate the main valve directlyby the valve-rope through a rack and pinion, as shown in Fig. 5, inwhich A is the hydraulic cylinder; B, the car; 0, a section through themiddle of the main valve; N, the circulating-pipe; O, thedischarge-pipe; K, the valve-rope, and W J the rack and pinion. In thismethod, as in that shown in Fig. 1, the valve-rope is moved so as toclose the valve and stop the elevator by having clamped upon it lugsR,which engage with the cushioned sliding fork S, and are carried alongbythe car until the valve becomes closed and the car stopped. This valveis of peculiar construction, L, G, and L being solid pistons on thevalve-stem I, on which is the rack W; Y, the orifice or port throughwhich the water enters from the circulating-pipe N m, the portcommunicating with the cylinder, and Z the discharge-port. It is obviousthat this valve is balanced, except as regards the pressure from thecylinder on the solid piston O, which produces a corresponding amount offriction between the other side of the piston and the surfacen. It wouldprobably be better to make the valve entirely balanced by replacing thesolid piston Q by two short pistons, such as L, placed at the samepoints on the stem as the ends of the piston 0, allowing the water toenter between them, and so avoiding friction. The

valve is here shown in the central position, with communication to thebottom of the cylinder shut off. By turning the pinion J, therebydepressing the piston O, the water. is allowed to enter thecylinder-bottom through the port at from the space a, or, by raising thepiston O, to discharge from the cylinder-bottom through the port on andthe spacey. The peculiarity of this valve is the shape of the portcommunicating with the cylinder-bottom, the edge of which, behind theblock 0, is shown by the dotted curve 1' s, and the shape of which isshown in the diagram, Fig. 6. This dia-,

gram represents the cylindrical surface of the valve through which theport-hole is cut, developed, or spread out fiat, and the upper end, a w,of the piston G, which has been depressed to its lowest position, so asto open the upper half of the port or hole at, and allow the water toflow from the space a into the cylinderbottom. To discharge the waterfrom the 05 linder-oottom the piston O is raised so as to' cover theupper half,m t, of the port and open the lower half, at Z. The reasonfor making the port this shape, which should theoretically be that of asurface hounded by two parabolas and two straight lines, tand Z, is thatas the valve closes the car moves more slowly, and consequently movesthe valve itself more slowly, so that in order to stop the car with auniform retardation the orifice through which the water flows shoulddiminish in area uniformly, notwithstanding the change in speed of thevalve itself. It is important in this method to have the fork S properlycushioned, either by springs, air-cushions, or dash-pots, for obviousreasons.

In Fig. 5 the piston'X is shown covering the orifice through which thewater enters the bottom of the cylinder; but we disclaim this as new,having been anticipated by O. E. Merrill in his United States Patent No.235,693.

Fig. 7 is an elevation of our apparatus intended to automaticallyregulate the speed of the descending car, according to its load, throughthe intervention of a stop, limiting the opening of the valve by thevalve-rope, the position of which stop is affected by the amount of loadin the car. B is the car; D, the hoistingropes,which, as usual, passover pulleys E and F; K, the valve-rope, passing over pulleys I As thevalve'rope K has clamped upon it a lug,

S,which limits the opening of the, valve, so as to cause the car todescend by striking the arm Q, it is clear that the greater the load inthe car the higher will the frame J H and the arm Q be raised by thedeflected ropes D against the tension of the spring P and the less canthe valve be opened. If it were also desired to use the same device toregulate the speed of ascent, it would only be necessary to clampanother lug below the arm Q, which will then determine the opening ofthe valve in the other direction, according to the load in the car. Itwould be better to use a weight hung on the frame J H, instead ot'aspring for the deflecting force, and also to have the deflectionconsiderably greater than thedrawings show. The object of the dash-pot Nis to prevent-jouncing of the car when the car is stopped. Anothermethod of efl'ecting the opening of the valve by the load in the carwould be by the diminished pressure on the water in the cylinder belowthe piston, caused by more weight in the car acting on an auxiliarypiston limiting the opening of the valve against a spring.

\Ve claim- 1. A hydraulic elevator consisting of amovable car orplatform and apparatus for raising and lowering the same by means ofhydraulic pressure acting in a cylinder upon a piston, in combinationwith astarting and stopping apparatus controlled by the operator andconstructed so as to automatically start the car with a fixedacceleration and to stop the car with a fixed retardation, independentlyof the speed at which the controlling mechanism is worked by theoperator, substantially as described.

2. A hydraulic elevator, substantially as described, in combination witha starting and stopping apparatus controlled by the operator andconstructed to close and open the valve which controls the flow of waterinto and out of the cylinder at a fixed speed or speeds, independentlyof the speed at which the controlling mechanism is worked by theoperator, substantially as described.

3. A hydraulic elevator, substantially as described, in combination withthe stopping apparatus controlled from the car and constructed to actautomatically to close the valve ata uniform rate, so as to insure thebringing of the ear to rest with its platform at the level of thedesired floor, substantially as and for the purposes described.

4. In a hydraulic elevator consisting of a movable car or platform andapparatnsfor raising and lowering the same by means of hydraulicpressure acting in a cylinder upon a piston, the combination, with avalve controlling the flow of water into and out of the said cylinder,of a supplementary cylinder provided with a piston moved byfluid-pressure under the control ofthe operator, substantially asdescribed, and mechanically connected to the said valve, so that themovement of the supplementary piston closes and opens the said valve,substantially as described.

5. The combination, with the cylinder of a hydraulic elevator, of avalve having a tapering port of gradually-increasing width in thedirection of motion of the valve-piston, substantially as shown anddescribed, so that the gradually-diminishing speed of the valve-pistonwill effect the closing of the port-orifice at auniform rate,substantially as described.

6. A hydraulic elevator, substantially as described, in combination withan apparatus for automatically regulating the size of orifices throughwhich the water flows into and out of the cylinder according to the loadin the car, substantially as described.

CHARLES G. CURTIS. SOHUYLER S. WHEELER. Witnesses:

CHARLES E. SPRAGUE, O'r'ro BAUMANN.

